Aryl Ferrophites – A New Class of Ligands for Asymmetric Catalysis

Enantiopure lithiated 1,2‐ferrocenes, [CpFe{1,2‐η 5 ‐C 5 H 3 (Ar)(Li)}] (Ar = Ph, 4‐CF 3 C 6 H 4 , 1‐C 10 H 7 ), react readily with PhOP(OR) 2 to yield [CpFe{1,2‐η 5 ‐C 5 H 3 (Ar)P(OR) 2 }] (R = Ph, 1,1′‐biphenyl‐based, 1,1′‐binaphthyl‐based) efficiently. Traditional routes to these species, involving the use of chlorophosphites ClP(OR) 2 were found to be ineffective. These “ferrophite” ligands have been characterised by X‐ray crystallography (4 examples) and shown to be effective in both nickel‐catalysed addition of AlMe 3 to PhCHO (up to 77 % ee ) and copper( I )‐catalysed additions of organoaluminium reagents to enones (up to 92 % ee ). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)